This renewal proposal seeks support to build upon our present resource interdisciplinary expertise, collaborative biomedical projects with UCSF clinicians and biomedical scientists and our computerized high resolution mass spectrometry capabilities for the benefit of western bio-organic and biomedical research groups who lack regional access to either/or both the mass spectrometry expertise or such unique facilities. We will seek to stimulate the application and usage of real-time high resolution gas chromatography/high resolution mass spectrometry both on a collaborative and service basis to fulfill existing accurate mass measurement (elemental composition) requirements even for labs which already have GC/MS information on their samples. The proposed mass spectrometer (Kratos/AEI MS 50) will provide faster scan cycle time (5-6 sec at m/delta m 10,000) or larger mass range (greater than m/e 800) and higher resolutions (less than or equal to m/delta m 100,000). Using the former, elemental composition chromatography (ECC) will be developed and exploited for complex mixture analyses. LOGOS-II will handle the higher data acquisition (less than or equal to 100 KHz) and processing load and preserve mass measurement accuracy (32 bit exponentiation). Utilizing the proposed high field magnet with EI FD (with or without a source collision cell), we plan to develop and make available the instrumental capability and expertise for obtaining mass spectral information on high mass bio-organic substances at high sensitivity (8 Kv). Most of the biologically active oligomers or active sequences there of - peptides, nucleosides, saccharides and mixed molecular species -viz. liposaccharides, lipopeptides, etc., fall in the range of 1000-5000 amu. Specific areas of clinical importance which are being pursued include diagnosis and study of gene diseases; Vitamin D3 metabolism, bile acid metabolism and endocrinology.